This article presents the results of an empirical study of intentional homicide cases in Missouri. The authors created a database of 1046 cases; it includes substantially all of the homicide cases prosecuted in Missouri over a five year period that were initially charged as murder or voluntary manslaughter and that yielded criminal convictions. The authors selected 247 cases from the larger database for more detailed analysis. We analyzed geographic and racial disparities in the rates at which: prosecutors charge first-degree murder versus lesser charges; prosecutors seek the death penalty, not lesser punishments; defendants are convicted of first-degree murder versus lesser crimes; and defendants are sentenced to death, not lesser punishments.

The Missouri statute gives prosecutors very broad discretion. We estimate that at least 76 percent of the cases in the database are death-eligible under the statute. However, prosecutors pursued capital trials in only about five percent of the cases. Thus, death-eligible cases in which prosecutors chose not to pursue capital trials comprise at least 71 percent of the cases in the database. Prosecutors in different counties exercise their discretion differently, leading to substantial variation in charging and sentencing practices in different counties across the state. The analysis of cases by race of victim and race of defendant shows that there are racial disparities in charging and sentencing decisions, but the racial disparities are not as significant as the geographic disparities. The article presents measures of racial and geographic disparities without controlling for individual culpability; a follow-on study will introduce culpability measures as control variables.